The present invention concerns a control circuit for the synchronous or alternate activation of at least two flash devices each consisting of a flash generator and at least one flash means, by flash activating signals of a camera at the input of the control circuit via outputs of the control circuit electrically connected to the control inputs of the flash generators.
Control circuits of this kind are used in particular in fields of professional photography in connection with studio flash systems, the use of such control circuits not being confined to the fields mentioned. Usually the flash systems comprise several flash means which are supplied via corresponding flash generators to activate flashes. The control inputs of the flash generators are in turn connected to the outputs of the control circuit, so that for activating flashes, for example by a camera, by corresponding flash request signals at the input of the control circuit flash activating signals are generated at the control circuit outputs.
The maximum number of flashes that can be activated per unit of time is limited by the recharging time of the individual flash generators. After activation of a flash and the associated discharge of the storage elements of the respective flash generator, a length of time passes for recharging the storage elements until the flash generator is ready for activating a flash again.
From German patent document DE 4433686C1 is known a studio flash system having a plurality of function elements which comprise one or more electronic control means for the control of several flash devices. It is known that different configurations of a flash system consisting of power supply units, storage elements, flash heads and electronic control means can be controlled electronically. In this case, for example an electronic control means is supplied by a power supply unit which controls several flash devices composed of storage elements and flash heads.
The voltage supply of the known electronic control means is via external or internal power supply units or other voltage sources, for example batteries or accumulators. A drawback is that the electronic control means have to be supplied with electricity via an additional power supply unit or, in the case of an integrated power supply unit, via additional lines. If batteries or accumulators are used, the control means must first be equipped with full batteries or charged up before use. If they are not used for a long time, it must be assumed because of automatic discharge that the electronic control means is not ready for use after some time of not being used because of discharged batteries or accumulators. A further drawback arises from the fact that the electronic control means must have an interface configured and adapted to the respective configuration of power supply units, storage elements and flash heads.